Adsorption type refrigerator that automatically determines switchover point

ABSTRACT

The present invention discloses an adsorption type refrigerator that automatically determines the switchover point. The adsorption type refrigerator includes a first vacuum chamber, a second vacuum chamber, a third vacuum chamber and a waterway structure. The waterway structure is connected to a first adsorption bed in the first vacuum chamber and a second adsorption bed in the second vacuum chamber. The waterway structure simultaneously conveys hot water into the first adsorption bed and cold water into the second adsorption bed, or simultaneously conveys cold water into the first adsorption bed and hot water into the second adsorption bed so as to allow the first and the second adsorption beds to conduct adsorption and desorption alternatively. This alternation creates pressure variation in the three vacuum chambers, which is then utilized to automatically determine the switchover point at which the refrigerator can provide and maintain a cold, stable environment.

BACKGROUND OF THE INVENTION

1. Technical Field

The present invention relates to adsorption type refrigerators, and more particularly, to an adsorption type refrigerator that automatically determines the switchover point so as to provide and maintain a cold, stable environment.

2. Description of Related Art

An adsorption type refrigerator is composed of adsorption beds, condensers, and evaporators. The adsorption type refrigerator works by importing cold water to cool down the adsorption beds so that porous matter (e.g. silica gel, zeolite or active carbon) in the adsorption beds adsorbs a refrigerant, which is typically a gaseous heat-transferring medium (e.g. water, methanol, ethanol or ammonia). When the heat-transferring medium evaporates and adsorbs a huge amount of latent heat of evaporation from the ambient environment, the adsorption type refrigerator effects refrigeration.

When saturated and no more capable of adsorption, the adsorption beds must be heated for desorption, and at the same time the evaporated refrigerant is condensed for reuse. Solar energy or industrial waste energy may be used as the heat resource for desorption of the adsorption beds and hence the heat source for refrigeration, thereby answering to the worldwide trend of environmental protection and energy preservation.

Conventionally, in order to effect continuous refrigeration, an adsorption type refrigerator has at least two adsorption beds that conduct adsorption and desorption alternatively. However, when any of the adsorption beds performs adsorption or desorption at the limit of its adsorption or desorption capacity, the adsorption type refrigerator is actually incapable of refrigeration, even though there is still circulation between cold water and hot water. As a result, not only is the overall refrigeration efficiency of the adsorption type refrigerator lowered, but also the excessively introduced cold water may over cool the adsorption beds and freeze the refrigerant, which in turn shortens the service life of the adsorption type refrigerator.

Additionally, even if the two adsorption beds have similar configures and materials, their performances of adsorption or desorption are usually different. Because of that, the optimal refrigeration efficiency of the adsorption type refrigerator cannot be ensured even by setting parameters that lead to automatic switchover between the adsorption beds. Hence, a major challenge facing adsorption type refrigerators is to effectively and accurately determine the switchover point of adsorption and desorption between the two adsorption beds.

SUMMARY OF THE INVENTION

The present invention provides an adsorption type refrigerator that automatically determines the switchover point, wherein by detecting pressure gradients inside each vacuum chamber, a valve switchover point can be determined so as to not only identify the preferred switchover point of the adsorption type refrigerator, but also improve the refrigeration stability of the adsorption type refrigerator.

To achieve the above effects, the present invention provides an adsorption type refrigerator that automatically determines the switchover point. The adsorption type refrigerator comprises: a first vacuum chamber having a first adsorption bed, a first condenser, a first evaporator, and a first vacuum gauge, wherein the first adsorption bed has a first inlet and a first outlet, and the first vacuum gauge serves to measure a first vacuum pressure inside the first vacuum chamber; a second vacuum chamber abreast with the first vacuum chamber and having a second adsorption bed, a second condenser, a second evaporator, and a second vacuum gauge, wherein the second adsorption bed has a second inlet and a second outlet, and the second vacuum gauge serves to measure a second vacuum pressure inside the second vacuum chamber; a third vacuum chamber having a top connected to bottoms of the first vacuum chamber and the second vacuum chamber and including a third evaporator and a third vacuum gauge, wherein the third evaporator has an ice water inlet and an ice water outlet, and the third vacuum gauge serves to measure a third vacuum pressure inside the third vacuum chamber; and a waterway structure comprising a plurality of pipes and a plurality of valves, wherein the pipes are mutually connected through the valves, and the valves are switchable between a first position for simultaneously conveying hot water into the first adsorption bed and cold water into the second adsorption bed and a second position for simultaneously conveying the cold water into the first adsorption bed and the hot water into the second adsorption bed. When the first vacuum pressure reaches a minimum, the valves are switched to the first position, and when the second vacuum pressure reaches the minimum, the valves are switched to the second position.

Implementation of the present invention at least achieves the following advantageous effects:

1. The preferred switchover point for the adsorption beds can be accurately and automatically identified by detecting the vacuum pressures inside the vacuum chambers.

2. By effectively identifying the preferred switchover point for the adsorption beds, the refrigeration efficiency of the adsorption type refrigerator can be improved.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention as well as a preferred mode of use, further objectives and advantages thereof will be best understood by reference to the following detailed description of illustrative embodiments when read in conjunction with the accompanying drawings, wherein:

FIG. 1 and FIG. 2 are schematic drawings showing the operation of an adsorption type refrigerator that automatically determines the switchover point according to a first aspect of the present invention; and

FIG. 3 through FIG. 6 are schematic drawings showing the operation of an adsorption type refrigerator that automatically determines the switchover point according to a second aspect of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 and FIG. 2 show the operation of an adsorption type refrigerator 100 that automatically determines the switchover point according to a first aspect of the present invention while FIG. 3 through FIG. 6 show the operation of an adsorption type refrigerator 100 that automatically determines the switchover point according to a second aspect of the present invention.

As shown in FIG. 1, the present embodiment is an adsorption type refrigerator 100 that automatically determines the switchover point. The adsorption type refrigerator 100 comprises: a first vacuum chamber 10, a second vacuum chamber 20, a third vacuum chamber 30, and a waterway structure 40.

The first vacuum chamber 10 includes: a first adsorption bed 11, a first condenser 12, a first evaporator 13, and a first vacuum gauge 14. The first adsorption bed 11 has a first inlet 11 a and a first outlet 11 b. The first vacuum gauge 14 serves to measure a pressure inside the first vacuum chamber 10 and identify the pressure as a first vacuum pressure.

The second vacuum chamber 20 is set abreast with the first vacuum chamber 10. The second vacuum chamber 20 includes: a second adsorption bed 21, a second condenser 22, a second evaporator 23, and a second vacuum gauge 24. The second adsorption bed 21 has a second inlet 21 a and a second outlet 21 b. The second vacuum gauge 24 serves to measure a pressure inside the second vacuum chamber 20 and identify the pressure as a second vacuum pressure.

The first condenser 12 and the second condenser 22 correspond in position to the first adsorption bed 11 and the second adsorption bed 21, respectively. The first condenser 12 and the second condenser 22 share a conjoint condenser tube 60 that is configured through both the first vacuum chamber 10 and the second vacuum chamber 20. The condenser tube 60 allows cold water to flow therethrough from the first condenser 12 to the second condenser 22, where the cold water is discharged.

Each of the first evaporator 13 and the second evaporator 23 has: at least one evaporator tray 131 or 231 and a heat-transferring pipe 132 or 232. The evaporator trays 131 and 231 serve to carry a heat-transferring medium. The heat-transferring pipes 132 and 232 are coiled on the evaporator trays 131 and 231, respectively. Each of the heat-transferring pipes 132 and 232 has its two ends (not shown) communicating with a third vacuum chamber 30, so that a gasified heat-transferring medium inside the third vacuum chamber 30 can flow into the heat-transferring pipes 132 and 232 to transfer heat to the heat-transferring medium in the evaporator trays 131 and 231, respectively. In the present embodiment, the heat-transferring medium is water.

The third vacuum chamber 30 has its top connected to bottoms of the first vacuum chamber 10 and the second vacuum chamber 20. The third vacuum chamber 30 has therein a third evaporator 31 and a third vacuum gauge 32. The third evaporator 31 includes an ice water inlet IWI and an ice water outlet IWO. Ice water is introduced through the ice water inlet IWI to evaporate and gasify the heat-transferring medium; consequently the ice water is cooled. Afterward, the cooler ice water is led out through the ice water outlet IWO. The third vacuum gauge 32 serves to measure a pressure inside the third vacuum chamber 30 and identify the pressure as a third vacuum pressure.

The third evaporator 31 comprises at least one evaporation heat-exchanging tray 311 and a heat-exchanging pipe 312. The evaporation heat-exchanging tray 311 also carries a heat-transferring medium, while the heat-exchanging pipe 312 has its two ends connected to the ice water inlet IWI and the ice water outlet IWO, respectively. The heat-exchanging pipe 312 is coiled on each evaporation heat-exchanging tray 311.

While the ice water enters the heat-exchanging pipe 312 through the ice water inlet IWI and gasifies the heat-transferring medium in the evaporation heat-exchanging tray 311, the ice water gasifies the heat-transferring medium and is thus cooled. The gaseous heat-transferring medium rises and enters the heat-transferring pipes 132, 232 to conduct heat exchange with the heat-transferring medium in the evaporator trays 131, 231. Then, the heat-transferring medium in the heat-transferring pipes 132, 232 is condensed into liquid and drops back to the evaporation heat-exchanging tray 311.

The waterway structure 40 comprises a plurality of pipes 41 and a plurality of valves 42. The pipes 41 are in mutual communication through the valves 42. The valves 42 have a first position and a second position. When the valves 42 are in the first position, hot water is conveyed into the first adsorption bed 11, and cold water is conveyed into the second adsorption bed 21 simultaneously. When the valves 42 are in the second position, the cold water is conveyed into the first adsorption bed 11, and hot water is conveyed into the second adsorption bed 21 simultaneously.

With different designs of the pipes 41 and the valves 42, the present embodiment performs different refrigeration operations so as for the adsorption type refrigerator 100 to provide stable refrigeration.

As shown in FIG. 1 and FIG. 2, in a first aspect of the present embodiment, the valves 42 in the waterway structure 40 of the adsorption type refrigerator 100 include a first valve 42 a, a second valve 42 b, a third valve 42 c, and a fourth valve 42 d.

The first valve 42 a guides hot water from the hot water inlet HWI into the first inlet 11 a or the second inlet 21 a, thus causing the corresponding adsorption bed 11 or 21 to conduct desorption. The second valve 42 b brings the first outlet 11 b or the second outlet 21 b into communication with the hot water outlet HWO, so as to guide the hot water outward. The third valve 42 c allows cold water to flow from the cold water inlet CWI into the first inlet 11 a or the second inlet 21 a, thus causing the corresponding adsorption bed 11 or 21 to conduct adsorption. Then, the fourth valve 42 d brings the first outlet 11 b or the second outlet 21 b into communication with the cold water outlet CWO and thereby guides the cold water outward.

Referring to FIG. 1, the valve 42 is at the first position. The first valve 42 a guides hot water from the hot water inlet HWI to the first inlet 11 a, so the first adsorption bed 11 conducts desorption. The second valve 42 b then guides the hot water from the first outlet 11 b to the hot water outlet HWO, so the first vacuum pressure inside the first vacuum chamber 10 rises gradually. At the same time, the third valve 42 c guides cold water from the cold water inlet CWI to the second inlet 21 a and thus makes the second adsorption bed 21 conduct adsorption. At last, the fourth valve 42 d guides the cold water from the second adsorption bed 21 to the cold water outlet CWO. As cold water is continuously introduced into the second adsorption bed 21 to cause adsorption of the second adsorption bed 21, the second vacuum pressure inside the second vacuum chamber 20 decreases over time.

When the second vacuum pressure reaches a minimum, which means the second adsorption bed 21 has reached adsorption saturation and is not capable of adsorption anymore, the valves 42 are switched to the second position. At this time, the second vacuum pressure is lower than the third vacuum pressure, and the third vacuum pressure is lower than the first vacuum pressure.

As show in FIG. 2, the valve 42 is at the second position. The third valve 42 c guides cold water from the cold water inlet CWI to the first inlet 11 a, so the first adsorption bed 11 conducts adsorption. Then, the fourth valve 42 d guides the cold water coming from the first adsorption bed 11 to flow out through the cold water outlet CWO, so the first vacuum pressure inside the first vacuum chamber 10 gradually decreases. The first valve 42 a guides hot water to the second adsorption bed 21, so as to make the second adsorption bed 21 conduct desorption. Afterward, the second valve 42 b guides the hot water coming from the second adsorption bed 21 to flow out through the hot water outlet HWO, so the second vacuum pressure inside the second vacuum chamber 20 also rises over time.

When the first vacuum pressure reaches a minimum, which means the first adsorption bed 11 is saturated and incapable of adsorption and hence the first vacuum pressure cannot decrease anymore, the valves 42 are switched back to the first position. At this time, the first vacuum pressure is lower than the third vacuum pressure, and the third vacuum pressure is lower than the second vacuum pressure. The adsorption type refrigerator 100 continuously operates in this manner to provide continuous refrigeration.

Referring to FIG. 3 through FIG. 6, in a second aspect of the present embodiment, the valves 42 in the waterway structure 40 of the adsorption type refrigerator 100 include a fifth valve 42 e, a sixth valve 42 f, a seventh valve 42 g, an eighth valve 42 h, a ninth valve 42 i, and a tenth valve 42 j.

Compared with the first aspect, the second aspect has two additional valves, which allow the adsorption type refrigerator 100 to conduct heat recovery. The heat recovery is conducted before the adsorption bed 11 or 12 conducts adsorption, so as to cool the adsorption bed 11 or 12 in advance and thereby improve the refrigeration efficiency of the adsorption type refrigerator 100.

The fifth valve 42 e is connected to the hot water inlet HWI for guiding hot water to the sixth valve 42 f or the seventh valve 42 g. The sixth valve 42 f is connected to the fifth valve 42 e as well as the hot water outlet HWO. The sixth valve 42 f serves to guide the hot water introduced through the fifth valve 42 e or the eighth valve 42 h to the hot water outlet HWO for discharge.

The seventh valve 42 g is connected to the fifth valve 42 e and is also connected to the first inlet 11 a and the second inlet 21 a. By controlling the seventh valve 42 g, hot water coming from the hot water inlet HWI is guided to the first adsorption bed 11 or the second adsorption bed 21. Or, by controlling the seventh valve 42 g, cold water coming from the eighth valve 42 h is guided to the first inlet 11 a or the second inlet 21 a. The eighth valve 42 h is connected to the sixth valve 42 f and is also connected to the first outlet 11 b and the second outlet 21 b. The eighth valve 42 h is further connected to the seventh valve 42 g by means of a bypass pipe 41 a.

The bypass pipe 41 a serves to connect the pipe between the eighth valve 42 h and the sixth valve 42 f with the pipe between the fifth valve 42 e and the seventh valve 42 g. In addition, the bypass pipe 41 a is a one-way pipe, so water in the bypass pipe 41 a can only flow from the eighth valve 42 h toward the seventh valve 42 g.

The ninth valve 42 i is connected to the seventh valve 42 g and also to the first inlet 11 a and the second inlet 21 a. By controlling the ninth valve 42 i, cold water coming from the cold water inlet CWI is guided to the first adsorption bed 11 or the second adsorption bed 21. The tenth valve 42 j is connected to the cold water outlet CWO and is also connected to the first outlet 11 b and the second outlet 21 b so as to guide the cold water to the cold water outlet CWO.

Referring to FIG. 3, the valves 42 are in the first position. By controlling the fifth valve 42 e and the seventh valve 42 g to guide hot water into the first adsorption bed 11, and controlling the eighth valve 42 h and the sixth valve 42 f to guide the hot water in the first adsorption bed 11 to the hot water outlet HWO, the first adsorption bed 11 conducts desorption and thereby increases the first vacuum pressure in the first vacuum chamber 10. At the same time, cold water is introduced into the second adsorption bed 21 through the ninth valve 42 i and guided to the cold water outlet CWO through the tenth valve 42 j, so the second adsorption bed 21 conducts adsorption, causing the second vacuum pressure inside the second vacuum chamber 20 to decrease gradually.

When the second vacuum pressure reaches a minimum, meaning that the second adsorption bed 21 has reached adsorption saturation and is no longer capable of adsorption, the valves 42 are switched to the second position. At this time, the second vacuum pressure is lower than the third vacuum pressure, and the third vacuum pressure is lower than the first vacuum pressure. Additionally, the present aspect may conduct heat recovery. A first heat recovery may be conducted before the valves are switched to the second position, so as to cool the first adsorption bed 11 in advance.

As shown in FIG. 4, the valves 42 are now in a state for the first heat recovery, where hot water is directly introduced through the hot water inlet HWI and instantly drained at the hot water outlet HWO by way of the fifth valve 42 e and the sixth valve 42 f; consequently, the hot water does not flow through any of the adsorption beds 11, 21. Cold water coming from the cold water inlet CWI runs through the ninth valve 42 i to the first adsorption bed 11 and, after passing through the eighth valve 42 h, the bypass pipe 41 a and the seventh valve 42 g, enters the second adsorption bed 21. Finally, the cold water passes through the tenth valve 42 j and is drained at the cold water outlet CWO.

Referring to FIG. 5, the valves 42 are now at the second position. Hot water flows through the fifth valve 42 e and the seventh valve 42 g and enters the second adsorption bed 21 by way of the second inlet 21 a. The hot water coming from the second adsorption bed 21 is guided to the hot water outlet HWO via the eighth valve 42 h and the sixth valve 42 f, so as to make the second adsorption bed 21 conduct desorption, thereby causing the second vacuum pressure inside the second vacuum chamber 20 to rise gradually. Meanwhile, cold water is introduced into the first adsorption bed 11 through the ninth valve 42 i and is drained at the cold water outlet CWO via the tenth valve 42 j, so the first adsorption bed 11 conducts adsorption and adsorbs the heat-transferring medium in the evaporator tray 131, causing the pressure inside the first vacuum chamber 10 to decrease gradually.

When the first vacuum pressure reaches a minimum, meaning that the first adsorption bed 11 is saturated and capable of no more adsorption and that the first vacuum pressure cannot decrease anymore, the valves 42 are switched back to the first position. At this time, the first vacuum pressure is lower than the third vacuum pressure, and the third vacuum pressure is lower than the second vacuum pressure. In addition, the present aspect may conduct a second heat recovery. The second heat recovery is conducted before the valves 42 are switched back to the first position, with a view to cooling the second adsorption bed 21 in advance.

A shown in FIG. 6, the valves 42 are in a state for the second heat recovery, where hot water is directly guided to the hot water outlet HWO via the fifth valve 42 e and the sixth valve 42 f without entering the first and second adsorption beds 11, 21. At the same time, cold water flows into the second adsorption bed 21 through the ninth valve 42 i and then passes through the eighth valve 42 h, the bypass pipe 41 a, and the seventh valve 42 g, before entering the first adsorption bed 11. At last, the cold water is drained at the cold water outlet CWO by way of the tenth valve 42 j.

More particularly, in the present aspect, a mass recovery valve 70 is provided between the first vacuum chamber 10 and the second vacuum chamber 20. The mass recovery valve 70 serves to communicate the first vacuum chamber 10 with the second vacuum chamber 20 for mass recovery.

When the first, second, and third vacuum pressures are to trigger the switching between the positions, the mass recovery valve 70 may be opened to communicate the first vacuum chamber 10 with the second vacuum chamber 20 so that the pressures in the two vacuum chambers 10, 20 are balanced rapidly. Therefore, the one conducting desorption can proceed with desorption, and the one conducting adsorption can further conduct adsorption, allowing the adsorption type refrigerator 100 to provide stable refrigeration at improved refrigeration efficiency.

Thus, when the vacuum pressure corresponding to the adsorption bed 11 or 21 that conducts adsorption reaches the minimum, it indicates that the adsorption bed 11 or 21 has completed adsorption and is incapable of adsorbing any heat-transferring medium and that the vacuum pressure cannot decrease anymore. Hence, the switchover point of the adsorption type refrigerator 100 can be determined by monitoring the vacuum pressures.

In addition, the adsorption type refrigerator 100 further comprises three adjusting pipes 50 that communicate with the first vacuum chamber 10, the second vacuum chamber 20, and the third vacuum chamber 30, respectively, for independently adding water into or vacuuming the first vacuum chamber 10, the second vacuum chamber 20, and the third vacuum chamber 30, respectively. Particularly, vacuuming and water supply are conducted successively prior to start-up of the adsorption type refrigerator 100.

The adsorption type refrigerator 100 also includes three drainage pipes 51 that communicate with the evaporator trays 131, 231 and the evaporation heat-exchanging tray 311, respectively, for draining the water carried by the trays 131, 231, 311 (i.e. the heat-transferring medium).

The present invention has been described with reference to the preferred embodiments, and it is understood that the embodiments are not intended to limit the scope of the present invention. Moreover, as the contents disclosed herein should be readily understood and can be implemented by a person skilled in the art, all equivalent changes or modifications which do not depart from the concept of the present invention should be encompassed by the appended claims. 

1. An adsorption type refrigerator that automatically determines a switchover point, the adsorption type refrigerator comprising: a first vacuum chamber having a first adsorption bed, a first condenser, a first evaporator, and a first vacuum gauge, wherein the first adsorption bed has a first inlet and a first outlet, and the first vacuum gauge serves to measure a first vacuum pressure inside the first vacuum chamber; a second vacuum chamber abreast with the first vacuum chamber and having a second adsorption bed, a second condenser, a second evaporator, and a second vacuum gauge, wherein the second adsorption bed has a second inlet and a second outlet, and the second vacuum gauge serves to measure a second vacuum pressure inside the second vacuum chamber; a third vacuum chamber having a top connected to bottoms of the first vacuum chamber and the second vacuum chamber, the third vacuum chamber having a third evaporator and a third vacuum gauge, wherein the third evaporator has an ice water inlet and an ice water outlet, and the third vacuum gauge serves to measure a third vacuum pressure inside the third vacuum chamber; and a waterway structure comprising a plurality of pipes and a plurality of valves, wherein the pipes are mutually connected through the valves, the valves being switchable between a first position for simultaneously conveying hot water into the first adsorption bed and cold water into the second adsorption bed and a second position for simultaneously conveying the cold water into the first adsorption bed and the hot water into the second adsorption bed; wherein the valves are switched to the first position when the first vacuum pressure reaches a minimum, and the valves are switched to the second position when the second vacuum pressure reaches the minimum.
 2. The adsorption type refrigerator of claim 1, wherein the valves include: a first valve for guiding the hot water coming from a hot water inlet to the first inlet or the second inlet; a second valve for communicating the first outlet or the second outlet with a hot water outlet; a third valve for guiding the cold water coming from a cold water inlet to the first inlet or the second inlet; and a fourth valve for communicating the first outlet or the second outlet with a cold water outlet.
 3. The adsorption type refrigerator of claim 1, wherein the valves include: a fifth valve connected to a hot water inlet; a sixth valve connected to the fifth valve and connected to a hot water outlet; a seventh valve connected to the fifth valve and connected to the first inlet and the second inlet; an eighth valve connected to the sixth valve and connected to the first outlet and the second outlet, wherein the eighth valve is further connected to the seventh valve through a bypass pipe; a ninth valve connected to the seventh valve and connected to the first inlet and the second inlet; and a tenth valve connected to the cold water outlet and connected to the first outlet and the second outlet; wherein the seventh valve guides the hot water coming from the hot water inlet to the first adsorption bed or the second adsorption bed, and the ninth valve guides the cold water coming from the cold water inlet into the first adsorption bed or the second adsorption bed.
 4. The adsorption type refrigerator of claim 1, wherein the first condenser and the second condenser share a conjoint condenser tube and the condenser tube is configured through the first vacuum chamber and the second vacuum chamber.
 5. The adsorption type refrigerator of claim 1, wherein each of the first evaporator and the second evaporator comprises: at least one evaporator tray for carrying a heat-transferring medium; and a heat-transferring pipe provided on each said evaporator tray and having two ends in communication with the third vacuum chamber.
 6. The adsorption type refrigerator of claim 1, wherein the third evaporator comprises: at least one evaporation heat-exchanging tray for carrying the heat-transferring medium; and a heat-exchanging pipe having two ends connected to the ice water inlet and the ice water outlet, respectively, the heat-exchanging pipe being provided on each said evaporation heat-exchanging tray.
 7. The adsorption type refrigerator of claim 1, further comprising three adjusting pipes, wherein each said adjusting pipe is in communication with the corresponding first vacuum chamber, second vacuum chamber, or third vacuum chamber, for independently supplementing water to or vacuuming the first vacuum chamber, the second vacuum chamber, or the third vacuum chamber. 